Trenching Assembly

ABSTRACT

An apparatus for cutting a trench is formed from a housing and a cutting assembly at least partially positioned within the housing. The cutting assembly has a cutting wheel and a plurality of teeth extending from the periphery of the cutting wheel. The cutting wheel features a plurality of layers of cylindrical profile in which at least two of the layers have profiles with different diametrical dimensions. At least some of the teeth are positioned on different layers. A trench is formed by placing the apparatus on a surface of the ground and pushing or pulling the apparatus while the cutting assembly is rotated. In one configuration, at least one layer having a profile of larger diametrical dimension is situated between a pair of layers having profiles of smaller diametrical dimension. In such configuration, the apparatus cuts a t-shaped trench.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/261,134 filed on Nov. 30, 2015, and claims thebenefit of U.S. Provisional Patent Application Ser. No. 62/245,705 filedon Oct. 23, 2015, and also claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/239,564 filed on Oct. 9, 2015, the entirecontents of which are incorporated herein by reference.

FIELD

The invention relates to tools and methods for cutting trenches in asurface of the ground.

SUMMARY

An apparatus is formed from a housing and a cutting assembly at leastpartially positioned within the housing. The housing has aground-engaging base in which an opening is formed. The cutting assemblyhas a cutting wheel and a plurality of teeth extending from theperiphery of the cutting wheel. The cutting wheel is formed from aplurality of layers of cylindrical profile in which at least two of thelayers have profiles with different diametrical dimensions. At leastsome of the teeth are positioned on the different layers.

An apparatus is also formed from a housing having a pair of first andsecond spaced side walls. Each side wall has an outer surface and aninner surface. The first side wall has an outer slot opening formed inthe outer surface and an inner slot opening formed in the inner surface.A slot extends through the first side wall between the outer slotopening and the inner slot opening. A plate is adjustably positionedover the outer slot opening. The plate is characterized by a raisedposition in which the plate uncovers a portion of the outer slotopening. The plate is further characterized by a lowered position inwhich the plate covers the portion of the outer slot opening. A motorassembly is supported on the plate. A cutting assembly is connected tothe motor assembly. The cutting assembly is at least partiallypositioned within the housing. A retractable cover extends over at leasta portion of the outer slot opening when the plate is in the raisedposition.

An apparatus is also formed from a housing and a cutting assembly atleast partially positioned within the housing. The housing has a pair ofopposed ends. Each end has a coupler in which the couplers are formed asmirror images with respect to a plane that extends through the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a cutting assembly partially positionedwithin a housing.

FIG. 2 is a side elevation view of the cutting assembly and housing ofFIG. 1.

FIG. 3 is a partial cross-sectional view of the housing of FIG. 1.

FIG. 4 is a perspective view of a trenching assembly showing anotherembodiment of the cutting assembly.

FIG. 5 is a side elevation view of the cutting assembly of FIG. 4.

FIG. 6 is a perspective view of the cutting assembly of FIG. 4.

FIG. 7 is a front elevation view of the cutting assembly of FIG. 4.

FIG. 8 is a front elevation view of two of the layers of the cuttingassembly of FIG. 7.

FIG. 9 is a perspective view of a trenching assembly.

FIG. 10 is a side elevation view of the trenching assembly of FIG. 8showing a plate in a lowered position.

FIG. 11 is a side elevation view of the trenching assembly of FIG. 8showing the plate in a raised position utilizing a cover.

FIG. 12 is a system for cutting a t-shaped trench into the ground.

DETAILED DESCRIPTION

Shown in FIG. 12 is a system 10 for cutting a narrow trench of varyingdepths and widths in a surface such as a concrete or asphalt roadway.The system 10 comprises a work machine 12 and a trenching assembly 14attached to the work machine 12. The trenching assembly 14 comprises ahousing 16 and a cutting assembly 18 (FIG. 1) rotatably positionedwithin the housing 16. The trenching assembly 14 attaches to the workmachine 12 via a linkage assembly. The work machine 12 may be any commontractor or work vehicle that can support the trenching assembly 14. Thework machine 12 shown in FIG. 12 comprises a tractor having wheels.However, the work machine 12 may be a tracked vehicle.

The system 10 further comprises a vacuum system 20. The vacuum system 20comprises a vacuum hose 22 and a vacuum power unit 24. The vacuum hose22 is attached to the trenching assembly 14. The vacuum system 20 may bemounted on the work machine 12 or the vacuum system 20 may be mounted onanother vehicle. The vacuum system 20 may comprise a cyclonic filtrationsystem to filter fine dust and increase power unit life.

Referring to FIGS. 1-4, the housing 16 of the trenching assembly 14 isformed from a strong and durable material, such as steel. The housing 16has a first side wall 26, a second side wall 28, an upper wall 30, and alower wall 32 positioned such that the walls form an internal cavity.The first and second side walls 26, 28 are spaced apart and parallel toeach other. The housing's upper and lower walls 30, 32 extend betweenthe spaced side walls 26, 28.

As best shown in FIGS. 3 and 4, the lower wall 32 has an outer face 34and an inner surface 36. An opening 38 is formed in the lower wall 32.The opening 38 extends between the lower wall's outer and inner surfaces34, 36. The opening 38 is fully enclosed by the lower wall 32. Adjacentthe opening 38, the lower wall's outer surface 34 is planar.

Providing a planar surface around the opening 38 enhances the degree ofground contact the housing 16 can maintain during a trenching operation.With good ground contact around a trench being formed, the housing 16stabilizes the ground and produces a cleaner cut. Good ground contactalso reduces escape of dust and debris from the housing 16

The lower wall 32 may comprise a skid plate positioned to cover thelower wall's outer surface 34. The skid plate is formed from a strongand durable material, such as steel. When the housing 16 is lowered, theskid plate engages the ground to reduce wear on the housing 16. For easeof replacement, the skid plate preferably is removably mounted on thehousing 16 via threaded connectors, such as bolts. When the skid plateis not used, the function of reducing wear may be accomplished byreinforcing the ground-engaging portion of the housing 16 with ahardened material.

As shown in FIGS. 1 and 3, the first side wall 26 has an outer surface40 and an inner surface 42. A slot 44 is formed in the first side wall26. The slot 44 extends between the first side wall's outer and innersurfaces 40, 42. Additionally, the housing 16 has a port 46 where thevacuum system 20 can attach to the housing 16 via the vacuum hose 22.Preferably, the port 46 is formed adjacent a site within the housing 16where spoils accumulate during trenching.

With reference to FIGS. 1, 2 and 4, the cutting assembly 18 ispositioned within the housing 16 such that a portion of the cuttingassembly 18 extends through the opening 38 in the lower wall 32. Thecutting assembly 18 comprises a cutting wheel 48 formed from a strongand durable material, such as steel. As shown in FIG. 5, a plurality ofopenings 50 are formed in the cutting wheel 48. The openings 50facilitate mounting the cutting wheel 48 on a motor via a connector,such as a hub.

With reference to FIGS. 5-7, the cutting wheel 48 is situated on alongitudinal axis. The cutting wheel 48 has a plurality of layers 52 inwhich each layer 52 has a cylindrical profile. Preferably, each layer 52has a center of rotation located on the longitudinal axis. The wheel 48and its layers 52 can be manufactured as a single piece, or the layers52 can be formed separately and bound together with a plurality ofconnectors 54 to form the wheel 48. Each layer 52 may comprise aplurality of curved segments 56 joined together to form a ring. Eachlayer 52 is characterized by a cylindrical profile having a singlediametrical dimension. Different layers may be characterized by profileshaving different diametrical dimensions.

Referring to FIG. 7, the cutting wheel 48 has a pair of opposed firstand second ends 58, 60. A pair of outer layers 62 are situated on theopposed ends 58, 60 of the cutting wheel 48, and three intermediatelayers 66, 68, 70 are situated between the pair of outer layers 62.Preferably the diametrical dimension of at least one intermediatelayer's profile is larger than the diametrical dimension of either outerlayers' profiles. Also preferably, the pair of outer layers 62 haveprofiles of the same diametrical dimension. As shown in FIG. 7, a firstintermediate layer 66 is characterized by a profile of a largerdiametrical dimension, while a second intermediate layer 68, a thirdintermediate layer 70, and the outer layers 62 are characterized byprofiles of a single smaller diametrical dimension.

The cutting assembly 18 further comprises a plurality of teeth 72positioned on the periphery of the cutting wheel 48. Preferably, theplurality of teeth 72 are mounted on each layer 52 of the cutting wheel48. Any number of teeth 72 may be mounted on a particular layer 52. Forexample, one of the outer layers 62 shown in FIG. 6 has fifteen teeth72. However, any suitable number of teeth 72 may be used.

The teeth 72 are formed from a strong and durable material, such assteel. The teeth 72 may be manufactured as a part of the cutting wheel48 or the teeth 72 may be attached to the cutting wheel 50 byconnectors, such as bolts, or by a fusion process, such as welding.Preferably, each tooth 72 has a tip 74 formed from diamond or carbide.In the embodiment shown in FIGS. 4-6, each tooth 72 comprises a base 76and a rotating bit 78 supported on the base 76. Each base 76 issupported on one of the plurality of layers 52.

FIG. 8 shows two of the layers 52 traversed by respective cross planes80 extending in parallel relationship. A first tooth 82 and a secondtooth 84 are supported on each layer 52. An angle is formed between eachtooth 82, 84 and the cross plane 80 of the layer 52 on which the tooth82, 84 is supported. The first and second teeth 82, 84 are situated suchthat they extend at different angles relative to the respective layer'scross plane 80. Returning to FIGS. 6 and 7, preferably, each of theteeth 72 are situated such that adjacent teeth 72 extend at differentangles relative to the respective layer's cross plane. Also preferably,each of the teeth 72 are oriented such that the tip 74 of each tooth 72is angled toward the direction of rotation when the cutting wheel 48 isrotated in a first direction about the longitudinal axis.

An additional type of tooth 72 that can be used is a polycarbonatediamond compact (PDC) cutter 73 as shown in FIG. 10. The PDC cutter 73may cover the entire width of the layer 52. In one embodiment using PDCcutters 73, two adjacent layers 52 having profiles of larger diametricaldimension are situated intermediate a pair of eight layers 52 havingprofiles of smaller diametrical dimension.

As shown in FIGS. 9-11, the trenching assembly 14 further comprises aplate 86 positioned over the slot 44. The plate 86 has an opening (notshown) that overlays the slot 44. A pair of guide elements 88 areconnected to the housing 16 and positioned in parallel relationship oneither side of the slot 44. The guide elements 88 support the plate 86no that the plate 86 is in slidable engagement with the housing 16.

The apparatus further comprises a motor assembly 90 supported on theplate 86. The motor assembly 90 comprises a motor 92 that powersrotation of the cutting wheel 48. A portion of the motor assembly 90extends into the housing cavity through the plate opening and the slot44. This projecting portion of the motor assembly 90 is mounted to thecutting assembly 18 within the housing cavity.

As shown in FIG. 10, the plate 86 is in a lowered position in which theslot 44 is entirely covered by the plate 86. In contrast, as shown inFIG. 11, the plate 86 is in a raised position in which a portion of theslot 44 is not covered by the plate 86. A depth adjustment deviceadjusts the position of the plate 86 relative to the housing 16. As theplate 86 is raised and lowered, the supported motor assembly 90, and itsconnected cutting assembly 18, are raised and lowered as well. The depthadjustment device may comprise a linear actuator, such as a jackscrew, ahydraulic cylinder, or a rack and pinion.

In FIGS. 9-10, the depth adjustment device comprises a jackscrew 96. Thejackscrew 96 has a leadscrew 98 having opposed first and second ends100, 102. A first end 100 of the leadscrew 98 is attached to the housing16 and a second end 102 of the leadscrew 98 is attached to the plate 86.Turning the leadscrew 98 in a first direction raises the plate 86relative to the housing's lower wall 32, and turning the leadscrew 98 inthe opposite direction lowers the plate 86 relative to the housing'slower wall 32. As shown in FIG. 11, the depth adjustment devicecomprises a hydraulic cylinder 105.

With reference to FIGS. 10 and 11, a cover 104, such as a flap for theslot 44 is shown. Preferably, the cover 104 is made from a flexiblematerial, such as rubber or plastic. The cover 104 may attach to thehousing 16. In another embodiment, the cover 104 attaches to the plate86. When the plate 86 is in a raised position shown in FIG. 11, thecover 104 is extended over the portion of the slot 44 that is notcovered by the plate 86. When the plate 86 is in a lowered positionshown in FIG. 9, the cover 104 is retracted.

Returning to FIGS. 1 and 2, the housing 16 has opposed first and secondends 106, 108. A pair of couplers 110 are situated on each of thehousing's ends 106, 108. In one embodiment, each coupler 110 comprises areceiver plate having a support panel 114, an upper flange 116, and alower flange 118 in which the flanges 116, 118 project from the supportpanel 114. Preferably, the upper flange 116 and the support panel 114define an included angle of 90 degrees or less. Also preferably, aplurality of openings 120 are formed in the lower flange 118.

The work machine 12 may attach to the coupler 110 by a hitchingmechanism. The hitching mechanism may comprise a mount plate that hooksthe upper flange 116 and latches onto the lower flange 118 via aplurality of pins extending through the plurality of openings 120.Preferably, the pins are spring-loaded. When the spring-loaded pins arepositioned over the openings 120, the pins automatically extend throughthe openings 120.

Continuing with FIG. 2, a vertical plane 122 traverses the housing 16and the cutting assembly 18. The pair of couplers 110 are formed asmirror images with respect to the plane 122. Mirror image couplers 110on opposed ends of the housing 16 are helpful on trenching jobs thatrequire alternating between pushing and pulling the trenching assembly14.

The couplers 110 allow the trenching assembly 14 to be disconnected fromone coupler 110 and re-connected at the other coupler 110 whentransition from pushing to pulling is required. The work machine 12 mayattach to one of the couplers 110 no that the trenching assembly 14 ispushed in a first direction. Alternatively, the work machine 12 mayattach to the other coupler 110 so that the trenching assembly 14 ispulled in the first direction. Positioning couplers 110 on both ends ofthe housing 16 is advantageous no that the trenching assembly 14 can bepushed or pulled in a given direction without changing the orientationof the cutting wheel 48 with respect to the trench. Keeping the cuttingwheel 48 in the same orientation with respect to the trench isparticularly desirable when the cutting wheel 48 is configured forrotation in a single direction.

FIG. 12 shows the system 10 in which the trenching assembly 14 is usedto form a t-shaped trench 124 in a surface of the ground 126. Thetrenching assembly 14 is attached to the work machine 12 and positionedon the ground 126. The motor assembly 90 rotates the cutting assembly 18while the work machine 12 pulls the trenching assembly 14 to form thetrench 124. The depth of the trench 124 is adjusted by raising orlowering the cutting assembly 18 via the depth adjustment device.

As the cutting wheel 48 breaks through the ground 126, spoils are formedin the trench 124 and turned up into the housing 16. Maintaining thelower wall 32 of the housing 16 in contact with the ground 126 helpscontain the spoils within the housing 16. Likewise, the cover 104 overthe slot 44 in the housing 16 helps to contain spoils. The spoils arecarried away by the vacuum system 20. Containing the spoils andvacuuming them away are beneficial to clean the trench 124 and to reducethe amount of dust and debris that escapes into the ambient air.

Changes may be made in the construction, operation and arrangement ofthe various parts, elements, steps and procedures described hereinwithout departing from the spirit and scope of the invention asdescribed in the following claims.

What is claimed is:
 1. An apparatus, comprising: a housing having aground-engaging base, in which an opening is formed in the base; and acutting assembly at least partially positioned within the housing andcomprising: a cutting wheel having a plurality of layers of cylindricalprofile in which at least two of the layers have profiles with differentdiametrical dimensions; and a plurality of teeth extending from theperiphery of the cutting wheel in which at least some of the teeth arepositioned on different layers.
 2. The apparatus of claim 1 in which thelayers are arranged such that a layer having a profile of largerdiametrical dimension is situated intermediate a pair of layers havingprofiles of smaller diametrical dimension.
 3. The apparatus of claim 1in which the cutting wheel has a pair of opposed ends and in which theplurality of layers further comprise: a pair of outer layers in whichone outer layer is situated adjacent each end; and an inner layersituated intermediate the outer layers.
 4. The apparatus of claim 3 inwhich the profile of the inner layer has a larger diametrical dimensionthan the profile of either outer layer.
 5. The apparatus of claim 1 inwhich the teeth extend through the opening formed in the base.
 6. Theapparatus of claim 1 in which at least two layers are traversed byrespective cross planes extending in parallel relationship, each of theat least two layers supporting at least two teeth that extend atdifferent angles relative to that layer's cross plane.
 7. A system,comprising: the apparatus of claim 1; and a t-shaped trench formed inthe ground and within which the cutting wheel is partially positioned.8. An apparatus, comprising: a housing having a pair of first and secondspaced side walls, each side wall having an outer surface and an innersurface, the first side wall having an outer slot opening formed in theouter surface, an inner slot opening formed in the inner surface, and aslot extending through the first side wall between the outer slotopening and the inner slot opening; a plate adjustably positioned overthe outer slot opening, the plate characterized by a raised position inwhich the plate uncovers a portion of the outer slot opening, and alowered position in which the plate covers the portion of the outer slotopening; a motor assembly supported on the plate; a cutting assemblyconnected to the motor assembly and at least partially positioned withinthe housing; and a retractable cover in which the cover extends over atleast a portion of the outer slot opening when the plate is in theraised position.
 9. The apparatus of claim 8, the cutting assembly,further comprising: a cutting wheel having a plurality of layers ofcylindrical profile in which at least two of the layers have profileswith different diametrical dimensions; and a plurality of teethextending from the periphery of the cutting wheel in which at least someof the teeth are positioned on different layers.
 10. The apparatus ofclaim 8 in which the housing has a lower surface having an opening andin which the cutting assembly extends through the lower surface opening.11. The apparatus of claim 8 in which the cover is flexible.
 12. Theapparatus of claim 8, further comprising: a device configured to movethe plate relative to the housing and to maintain the plate in a fixedposition at any selected point on its path of travel.
 13. The apparatusof claim 8, further comprising: a vacuum system having a hose; and aport formed in the housing in which the hose connects the housing to thevacuum system via the port.
 14. The apparatus of claim 10 in which thelower surface comprises: a skid plate.
 15. An apparatus, comprising: ahousing having a pair of opposed ends, each end comprising: a coupler inwhich the couplers are formed as mirror images with respect to a planethat extends through the housing; and a cutting assembly at leastpartially positioned within the housing.
 16. The apparatus of claim 15in which the plane traverses the cutting assembly.
 17. The apparatus ofclaim 15, the cutting assembly, further comprising: a cutting wheelhaving a plurality of layers of cylindrical profile in which at leasttwo of the layers have profiles with different diametrical dimensions;and a plurality of teeth extending from the periphery of the cuttingwheel in which at least some of the teeth are positioned on differentlayers.
 18. The apparatus of claim 15, further comprising: a workmachine in which the work machine is attachable to either coupler.